Added METRIC_TEST_IMAGE var

README.md

@@ -68,3 +68,7 @@ Running `make deploy` will deploy the daemonset and set up the configuration to
 ## Deploy on k8s
 
 Running `make deploy-k8s` will deploy the daemonset and set up the configuration to tie it to the Prometheus operator instance of an existing kubernetes cluster where the prometheus operator was deployed. Please note that the k8s version exposes metrics over a plain http port.
+
+## List of environment variables used in the tests
+
+- METRIC_TEST_IMAGE - path to generic container image used in tests 

test/network-metrics-daemon/network_metrics_daemon.go

@@ -57,7 +57,7 @@ var _ = ginkgo.Describe("NetworkMetricsDaemon", func() {
 					Containers: []corev1.Container{
 						{
 							Name:    "c1",
-							Image:   "quay.io/centos/centos",
+							Image:   consts.TestImage,
 							Command: []string{"/bin/bash", "-c", "sleep inf"},
 						},
 					},
@@ -226,7 +226,7 @@ var _ = ginkgo.Describe("NetworkMetricsDaemon", func() {
 					Containers: []corev1.Container{
 						{
 							Name:    "c1",
-							Image:   "quay.io/centos/centos",
+							Image:   consts.TestImage,
 							Command: []string{"/bin/bash", "-c", "sleep inf"},
 						},
 					},

test/utils/consts/consts.go

@@ -1,5 +1,17 @@
 package consts
 
+import "os"
+
+// TestImage contains test image (default is quay.io/centos/centos)
+var TestImage string
+
+func init() {
+	TestImage = os.Getenv("METRIC_TEST_IMAGE")
+	if TestImage == "" {
+		TestImage = "quay.io/centos/centos"
+	}
+}
+
 const (
 	// TestingNamespace contains the name of the testing namespace
 	TestingNamespace = "metrictest"

test/utils/pods/pods.go

@@ -62,7 +62,7 @@ func getDefinition() *corev1.Pod {
 		Spec: corev1.PodSpec{
 			TerminationGracePeriodSeconds: pointer.Int64Ptr(0),
 			Containers: []corev1.Container{{Name: "test",
-				Image:   "quay.io/centos/centos",
+				Image:   consts.TestImage,
 				Command: []string{"/bin/bash", "-c", "sleep INF"},
 			}},
 		},